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MG MGB GT V8 Factory Originals Technical - Fix it or Sell It

I have a beautifully restored 1980 mgb. There is one recurring problem; after a year, I think I'm ready to give up and sell it.
A little history; I purchased the car 10 years ago knowing it was perfect for a v8 conversion. 3 years ago, beautiful paint job, new interior, new top. Then a 3.9 aluminum block straight out of a Land Rover with less than 50k. I didn't do the work. A local mechanic I know for years did it, I did the research, he made it work.
Now the problem; after 2 hours on the road the car will stall when I come to a stop and will not start. If I keep the engine revved to prevent stalling, it will keep going for another 15 - 20 minute, it will then back fire and stall. Sometimes just resting the car for 3 or 4 hours, it would start
After a flatbed back to the shop (several flat beds back to the shop), my mechanic will swear up and down, he got this time. You can say get a new mechanic, but how does one vet out a new mechanic. The core problem was damaging some other electrical and mechanical within the car, he was fixing that and never got to the root problem.

Now this is the hard part, how much do you think I can get for my car?


The first thing to do with a non-starter is to try and find out why.

Is it cranking or not?

If it's cranking check you are getting a spark at each plug. If you are, check the power of the spark by seeing how far it will jump. It should jump at least 1/4".

Is this points or some electronic system? 6v ballasted coil or a 12v system? A mis-match here can cause weak sparking.

After cranking for a couple of minutes there should be a strong fuel smell around the car and in the exhaust.

What fuel system, carbs or injection?
Paul Hunt

If the engine cranks, follow the above to check for all the electrical to be good. I am putting my money on a bad coil. When it gets hot, it shorts out. If your mechanic has old time testing equipment such as a scope, have him put a load on it.

.... or a tired fuel pump.Recently mine would do an hour and a half before it got tired and gave up. It was new !
Roger W

Change them both & keep driving!
Carl Floyd

On that basis raise car by radiator cap, turn everything below cap one quarter turn clockwise, discard and replace. Then buy a new radiator cap.
Paul Hunt

"On that basis raise car by radiator cap, turn everything below cap one quarter turn clockwise, discard and replace. Then buy a new radiator cap."

Love it- Im going to use that one!
Innes Bint


Considering his state of mind after these issues, the cost of a coil & a fuel pump is minimal. Beside, who is gonna troubleshoot it for him?
Carl Floyd

This thread was discussed between 16/10/2014 and 12/04/2016

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